1. Field of the Invention
The present invention relates to a coater for applying a liquid or viscid medium to a moving surface (e.g., a fiber material web, applicator roll or backing roll), and, more particularly, to a coater for metering a coating mixture to a moving surface using a coater rod or coater blade.
2. Description of the Related Art
A coater for applying a liquid or viscid medium (such as coating color) to a moving surface may include a coating metering element in the form of a coater rod or coater blade which is positioned closely adjacent to the moving surface. The distance between the coater rod or coater blade and the moving surface during operation determines the thickness of the coating which is applied to the moving surface.
A coater rod is connected to a beam or mounting via a coater rod bed and a flexible support blade. The coater rod is rotatably carried by the coater rod bed and is driven in a rotational manner using an appropriate drive coupled with one or both ends of the rod. An air load tube positioned against the coater rod bed on a side generally opposite the coater rod biases the coater rod bed and coater rod toward the moving surface. The flexible support blade interconnects the coater rod bed with the mounting and is flexible to allow the coater rod to be moved toward and away from the moving surface using a solid profile bar and known adjustment devices, such as profile adjusting screws.
A coater blade is typically mounted directly to the mounting and is deflectable toward and away from the moving surface. An air load tube directly contacts the coater blade to bias the blade toward the moving surface. An eventually segmented profile bar bears on the air load tube. Each discrete segment is locally adjustable across the width of the coating blade in directions toward and away from the moving surface using known adjustment devices, such as profile adjusting screws.
With a metering element either in the form of a coater rod or a coater blade as described above, a profile bar dedicated exclusively for use with the corresponding type of metering element must be used. Thus, when it is desirable to switch from a coater blade to a coater rod, or vise versa, the profile bar which is designed for use with that particular type of metering element must be removed and replaced with a different type of profile bar. The process of removing one type of profile bar, installing another type of profile bar and adjusting the installed profile bar to within prescribed tolerances normally takes between 8 to 10 hours. This is obviously not desirable from an efficiency standpoint.
What is needed in the art is a coater having a profile bar assembly which is more readily adaptable for use with a metering element either in the form of a coater rod or a coater blade, and does not require extended change out times.